The present invention relates to a storage session management system in a storage area network (hereinafter, abbreviated as “SAN”) using Internet Protocol (hereinafter, abbreviated as “IP”). In the following description, SAN using IP is shown as IP-SAN.
A conventional technology for storage access is a fibre channel (hereinafter, abbreviated as “FC”) using a serial transfer system. In the following description, SAN using FC is shown as FC-SAN. In FC-SAN, when a failure occurs in a storage device, there is no serious problem even if a failure notification is issued to all the servers statically connected to the storage device. This is because that the failure notification is inherently limited to a particular range because a large scale network cannot be constructed due to the technical restriction of FC-SAN and that when a physical connection is established in FC-SAN, a logical connection is also established in general, there is no concept of a dynamically changing storage session.
However, when IP-SAN based on Internet SCIS (Internet small computer system interface, hereinafter, abbreviated as “iSCSI”) as shown in non-patent document 1 is used as a technology for storage access, even if there is a static connection, a dynamically changing storage session (hereinafter, abbreviated as “iSCSI session”) is not always established. Accordingly, when a failure occurs in, for example, a storage device, a problem arises in that a failure notification is issued to all the servers statically connected to the storage device. As a result, there is a possibility that since IP-SAN is excellent in network extensibility, the failure notification is issued to a very wide range and that, in the failure notification method, the failure notification is also sent to the servers which do not access to the failed storage device and thus are not affected by the failure. Therefore, a problem arises in that the failure notification places an excessive load on SAN or a burden is increased on the servers which receive the failure notification.
Next, a conventionally arranged management system in IP-SAN will be shown below.
[Patent document 1] U.S. Patent Application Publication No. 20030088683
[Non-patent document 1] RFC3720 Internet Small Computer Systems Interface (iSCSI).
As described in Description of the Related Art, when the failure notification method of conventional FC-SAN is used as it is in IP-SAN, a load on the network and the users is increased. Accordingly, to notify a failure without problems in IP-SAN, an iSCSI session management system is necessary to simultaneously manage static connection information and iSCSI session information that is dynamic connection information. Further, the iSCSI session management system is generally required to be less burdensome to a manager, the network, and the users.